I had some sips of green tea by accident, 4 days before surgery. Will I be okay?

Hello.  You should be fine, but it's still a good idea to let your surgeon know.  I expect him or her to reassure you and your surgery should go fine.  Take care.

Hi, thank you for your question. 
Herbal teas & supplements can increase you chances of bleeding. Rhinoplasty can be associated with bleeding normally so, I would absolutely mention this to your surgeon. “Some” small sips of green tea may not make a different. 
I hope this helps. Best of luck!